package domd4;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String str=in.nextLine();
            System.out.print(setString(str));
        }
    }
    private static String setString(String str){
        boolean[] flag=new boolean[127];//
        StringBuffer stringBuffer=new StringBuffer();
        for(int i=0;i<str.length();i++){
            char ch=str.charAt(i);
            if(flag[ch]==false){
                stringBuffer.append(ch);
                flag[ch]=true;
            }
        }
        return stringBuffer.toString();
    }
}